Pile tuft cutter for axminster looms



May 11, 1948. w. Y. ROBB FILE TUFT CUTTER FOR AXMINSTER LOOKS Filed Feb. 1, 1946 I B m MR m m T m w W m I 6 6 m Q 4 0 w mm 2 w ATTORNEY Patented May 11, 1948 PILE 'rUF'r CUTTER FOR AXMINSTER LOOMS Walter Y. Robb, Whltinsville, Mass., assignor to Crompton & Knowles Loom Works, Worcester, Mesa, a corporation of Massachusetts Application February 1, 1946, Serial No. 644,767

3 Claims. 1

This invention relates to improvements in tuft cutting mechanism for Axminster looms and it is the general object of the invention to provide such a mechanism with adjusting means which will be accurate, durable, and capable of holdvide a series of wedgesor tapered shims betweena knife and its supporting bar and construct the shims so that they can be moved by adjusting screws relatively to the bar to'afiect changes in the contour of the knife. The'shims and adjusting screws are preferably made to have direct operative engagement with each other, thereby providing a simple two-part adjustment for the knife.

It is another object of the invention to provide the adjusting screws with a mounting on the bar so located that the screws are in longitudinal alignment with the shims and to construct the supporting bar in such manner as to permit adjustment by the screws, preferably by means of a recess between a knife supporting rear shelf on the bar and a front screw supporting rib.

In-order to provide an inexpensive cutting blade'or'kn'ife I form the latter of a piece of flat metal and taper the rear edge thereof, leaving venient embodiment of my invention is set forth,

the forward part of the blade with parallel sides. Holding bolts pass through the bar, wedges and blade to hold these parts together in'jfixed position; It is a further object of my pie nt inv'ention to provide the aforesaid shelf witlifanf under surface inclined with respect to the forwardpart of the knife by an amount substantially equal to the taper of the shims, thereby enabling the holding bolts to be substantially perpendicular to the part of the blade through. which they pass to permit tight holding of the blade and the shims despite the vibration of the blade due to loom operation.

with these and other objects in view which will 'appear as the description proceeds, my invention resides in'the combination and arrangement of parts hereinafter described and set forth. 1

In the accompanying drawings, wherein a con- Fig. 1 is a side elevation partly in section of the forward upper part of an Axminster loom setting forth a front cutter bar provided with my invention,

Fig. 2 is a bottom plan looking in the direction of arrow 2, Fig. 1,

Fig. 3 is an enlarged detailed vertical section on line 3-3 of Fig. 2,

Fig. 4 is an enlarged fragmentary plan view of one of the adjusting shims and the adjusting screw corresponding thereto,

Fig. 5 shows one of the adjusting screws, and

Fig. 6 is a verticalsection on line 6-6 of Fig. 4.

Referring particularly to Fig. l, the m frame It supports a bridge member ll provided with front and back guides 12 and I3 for front and back knife or cutter bars l4 and I5, respectively. The fabric being woven is supported by a stationary nose board it and tufts not shown extending upwardly from the nose board in position to be cut from the tube frame not shown at the-end of a tuft forming operation; Prior to the cutting operation the front bar l4 will be to the left of the position shown in Fig. 1, while the rear bar i5 will be moved backwardly to the right, thereby providing space for the operation of the tube frame. The front bar will then be moved downwardly and rearwardly, as by a lever 18 and connector I9, while the rear bar will be moved forwardly by any approved mechanism not shown. The front bar is provided with a cutter blade 20 which engages a second blade 2| on the rear bar.

As a result of continued use the front knife may change the contour of its cutting edge sufliciently so that it does not engage the back knife at all points across the loom, and in order to correct this condition it is necessary to raise the low parts of the front knife. In a similar manner, if part of the front knife is too high it should be lowered to establish the correct cutting relation with the back knife.

Fig. 1 shows a specific relationship between the front and back cutting knives such as is found on a well-known type of Axminster loom, but I do not wish to be limited in the practice of my invention to the particular knife shown.

Referring more particularly to Figs. 2 and 3 and the under side of the knife bar l4, it will be seen that the latter is formed with a downwardly extending rib 25 extending along the forward part of the bar and is also formed with a backward extension 26 the lower part of which,

is formed with a depending shelf 21 which may be parallel to rib 25. A recess or depression 28 is formed in the under side of the bar l4 between the rib and the shelf 21.

The shelf 21 has an under surface 30 which engages the upper surfaces 3| of a series of tapered shims or wedges W the under surfaces 32 of which engage the flat top surface 23 of the knife 20. The forward part 34 of the bottom surface 35 of the knife is preferably parallel to the top surface 33, thereby facilitating manufacture of the knife out of a flat strip of steel which can be providedwith a reduced cutting rear part 36.

The thick forward part of each wedge W is provided with a vertically extending slot disposed transversely of the body of the wedge and open at its front end. The rear part of slot 40 opens into a wider slot 4| cut through the wedge and forming rear vertical walls 42 behind forward walls 43 on the front of the wedge and at the sides. of slot 40. The rib 25 has threaded therein a plurality of backwardly and forwardly extending adjusting screws 44 each having a screw driver slot 45 in the forward part thereof. The rear end of each screw has a head 45 connected to the body of the screw by a reduced neck 41. As shown more particularly in Figs. 3 and 4, each head 45 fits into the wide slot 4| behind walls 42, while the neck 41 extends forwardly through slot 40. The slot 4| may be slightly larger than the head 46 to provide a small amount of clearance. It will be apparent more particularly from Figs. 3 and 4 that the axis of the adjusting screws extends directly forwardly from the shims or wedges W, and that the rear threaded part 48 of screw 44 is in front of walls 43.

The upper part of the rear projection 25 of knife bar is provided with a longitudinal slot 50 extending over shelf 21 and arranged to receive the heads 5| of clamp bolts 52 which extend downwardly through the projection 25 and the shelf 21 and through slots 53 formed in the shims W and opening rearwardly as indicated in Fig. 2. Bolts 52 also extend through l ioles 55 in the forward part of the cutter blade 20, and nuts 56 on the lower ends of the bolts 52 afford means for clamping the parts together in the position shown in Fig. 3. The bolt heads 5| rest on a flat surface 51 at the bottom of slot 50. 1

In assembly, bar M will be inverted and rest on a support not shown to maintain the bolt heads 5| in slot 50. The screws 44' will then be threaded through rib 25 until heads 45 are adjacent to shelf 21. The shims W will then be placed on surface 30 with slots 53 aligned with bolts 52 and thereafter pushed rearwardly until slots 40 and 4| can fall in position around necks 41 and heads 45. Blade 20 is then placed over the shims with bolts 52 extending through holes 55 and the nuts 56 tightened to hold the blade and wedges in place. Bar I4 is then inverted and put in the loom. If any part of knife 20 is too low the corresponding shim will be moved forwardly by turning the associated screw with a screw driver not shown in slot 45. If, on the other hand, any part of the knife is too high the corresponding shim can be moved rearwardly .by an appropriate turning of the associated screw 44.

It will be apparent from Figs. 2, 3, and 4 that the screws 44 can be detached from their shims by a simple relative vertical motion in which the necks 41 will pass out of the open top or bottom endof slot 40, provided the screw is moved far enough forwardly to enable tilting of the shim until detachment is effected. This quick and easy detachment of the shims and screws not only facilitates original assembly but simplifies repairs.

Referring again to Fig. 3, it will be seen that back and forth movement of each adjusting screw is communicated directly to its shim, and since the axis of the screw is in substantial alignment longitudinally with the body of the shim there is no vertical force which might otherwise tend to move the shim vertically to an improper position. The recess 28 on the under side of the bar l4 not only provides room for the screws 44 but also simplifies machining the under side of shelf 21.

Surface 30 is preferably inclined with respect to surface 51 of slot 50 by an amount substantially the same as the taper of the shims, hence bottom surface 35, at least that part of it engaging screws 56, is parallel to surface 51, and all forces brought to bear upon the knife by the bolts 52 and nuts 56 will be in sufllcient balance to enable adjustments of the shims to be retained and not be disturbed by the vibration of the knife 20 incident to the repeated back and forth movements of the front knife bar H.

The heads 45 preferably have a diameter somewhat larger than the thickness of the forward parts of the shims, and the axial center of the heads is between the top and bottom surfaces of the shims, hence turning of the screws 44 will have little or no effect in exerting unbalanced vertical forces on the shims. If desired, the holes 55 may be conical as indicated in Fig. 3 and the nuts 56 can have correspondingly conically shaped upper surfaces 63. The slot 50 is narrow enough to prevent turning of the heads 5| of the bolts 52 when the nuts 56 are tightened.

Adjustments of the screws 44 can be held by lock nuts 55 which when tightened will press against the front of the rib 25 to prevent turning of the screws 44.

From the foregoing it will be seen that I have provided simple and effective means for adjust-- ing the tuft cutting knife of an Axminster loom with respectjzo its supporting bar. The tapered of the bottom surfaces of the shelf and the top I and bottom surfaces of the shims is such that the forward part of the knife is substantially parallel to the surface 51, and the bolts 52 are substantially perpendicular to surfaces 35 and 51, hence the heads 5| will be drawn-tightly against the surface 51 when the nuts 55 are tightened and the parts will retain their setting. Also, the recess 28 formed on the underside of the bar |4 not only provides room for the screws 44, but also facilitates machining of surface 30 on the bottom of the inverted shelf 21. Furthermore, the screws 44 can be readily detached from their shims by a simple vertical motion of the shims after the screws have been turned forwardly far enough to permit such motion of the shim. This separation of the two parts of the adjusting unit is further facilitated by the fact that the length of the shim is less than the distance between the rib 25 and shelf 21 Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled'in the art without departing from the spiritand scope of the invention and I do not wish to be limited to the details herein disclosed, but what I claim is:

1. In tuft cutting mechanism for the pile yarns of an Axminster loom having a cutter bar extending thereacross, an inverted shelf depending from and extending along the rear part of the bar, a rib depending from and extending along the front of the bar, a cutter blade secured to the bar under the shelf, a plurality of wedges between the-shelf and blade extending transversely of the shelf and movable backwardly and forwardly, each wedge having the front end opening forwardly through the front end of the.

wedge and having a wider part rearward of said front end, and an adjusting screw threaded in the rib and having a. head on the rear end thereof located in the wider part of said slot, each head and wedge being separable by vertical relative movement, any wedge when moved forwardly relatively to the other wedges by turning of the corresponding screw in said rib being movable vertically to effect disengagement from said corresponding screw due to the fact that the narrow part of the wedge is loose with respect to and movable vertically relatively to said shelf and blade.

2. In tuft cutting mechanism for the pile yarns of an Axminster loom having a cutter bar extending thereacross, an inverted shelf depending from and extending along the rear part or the bar, a rib depending from and extending along the front of the bar and spaced forwardly from the shelf, a cutter blade secured to the bar under the shelf, a plurality of wedges between the ledge in: screw for each wedge threaded into the rib and extending rearwardly therefrom and having a head on the rear end thereof forward of the shelf located in the wider part of thecorresponding slot and extending above and below the associated wedge, each head and wedge being separable by vertical relative movement, any wedge when moved forwardly relatively to the other wedges by turning of the corresponding screw in said rib being movable vertically with respect to its screw to effect disengagement from the screw due to the fact that the narrow part of the wedge is loose with respect to and movable vertically relatively to said shelf and blade.

3. In tuft cutting mechanism for an Axminster loom having a cutter Bar extending transversely thereof, said bar formed with a depending rib extending along the front part thereof and a depending shelf spaced rearwardly from the rib extending along the rear part of the bar, a tuft cutting blade extending along and under said shelf, an adjusting wedge located between the shelf and the blade and of less length measured transversely of the bar than the distance between the rib and shelf, an adjusting screw threaded into and extending rearwardly from the rib, and cooperating connections between the screw and the wedge so constructed that turning of the screw in one direction effects forward movement of the wedge transversely of the shelf and turning of the screw in the opposite direction effects rearward movement of the wedge transversely of the shelf, the screw when turned and blade extending transversely of the shelf and a movable backwardly and forwardly, each wedge having the front end thereof thicker than the rear end th'ereof and located intermediate the shelf and rib and having a slot extending ver-' sufficiently in said one direction moving the wedge to a position between the shelf and rib to permit removal of the wedge.

WALTER Y, ROBB.

REFERENCES CITED The following references are of record in the Y file of this patent:

UNITED STATES PATENTS 

